Such shifting devices are used with increasing frequency for automatic transmissions or automated motor vehicle transmissions because of the driving comfort that can be achieved with them. However, vehicles equipped with the motor vehicle transmissions are frequently exposed to the risk of being used by unauthorized persons because they are usually loaded with options. Increased efforts are therefore made to protect the motor vehicles. This can be done in a great variety of ways. One possible solution is to protect the shifting device against unauthorized use by means of selector lever locks. These are thus used to secure the vehicle against theft or unauthorized use, on the one hand, and they can also be used, on the other hand, to avoid hazardous operating errors on the part of the driver of the vehicle himself.
Selector lever locks for shifting devices, e.g., as a “Keylock” and/or “Shiftlock,” have been known; “Keylock” means that the selector lever is secured against movement in the parking position “P” and the ignition key for putting the motor vehicle into operation can be removed from the ignition lock in this parking position only.
By contrast, “Shiftlock” means that the selector lever can be moved from the parking position “P” and from a neutral position “N” only during the actuation of the brake and/or below a permissible speed limit in order to assume the selection function for other shift positions. This is achieved by means of locking members, which are actuated, e.g., individually or in a succession by program-controlled electromagnets. The shifting movement of the selector lever is thus possible in the case of such selector lever locks only as a function of preset parameters.
A shifting device for a motor vehicle transmission, in which both systems, “Shiftlock” and “Keylock,” are used, has been known from DE 196 01 442 C2. The shifting device comprises a selector lever for selecting different shift positions (P, R, N, D, 3, 2, . . . ), which is mounted in a housing pivotably around an axis. A first locking member and two additional locking members block the movement of the selector lever in different shift positions as a function of preset parameters, i.e., e.g., below a maximum allowable speedlimit, in order to avoid the accidental selection of the reverse gear from a forward gear in this case. An adjusting member designed as an electromagnet is used to actuate the locking members, and the electromagnet has an armature, which can be extended from the housing of the electromagnet on both sides and thus forms a locking member each, which can engage recesses of the selector level, on each side. The selector lever itself, in which the recesses are provided, is used as the locking element.
The redundant system of a selector lever lock which is described in the document has a rather complicated design as an embodiment for a special application. One drawback of this solution is, furthermore, that three locking members are used.